Ingram Nathaniel Washington Irvine ("Father Nathaniel") (July 8, 1849 - January 23, 1921) was born in Ireland and immigrated to America in 1865. He graduated from General Theological Seminary in New York City in 1874, after which he was ordained an Episcopal priest. He served in various Episcopal parishes for over 25 years.

On April 25, 1900, Irvine, then rector of St. John's Episcopal Church in Huntingdon, Pennsylvania, was defrocked by his bishop, Ethelbert Talbot, for "conduct unbecoming a clergyman." Irvine fought for five years to have himself reinstated, but was unsuccessful. In the fall of 1905, he was received into the Orthodox Church, and on November 5, 1905, he was ordained a priest by St. Tikhon (assisted by St. Raphael), at St. Nicholas Russian Orthodox Cathedral in New York City. Irvine took the name "Father Nathaniel," and he was placed in charge of "English work."

After his ordination, Irvine was a close advisor to St. Tikhon and St. Raphael, and he was a strong advocate of the use of English in church services. He reposed in New York City in 1921, at the age of 71.